1. Field of the Invention
The invention is directed to a quick mounting nut, formed preferably as a fastening system for mounting bolts threaded rods which hang down in installation rails.
2. Description of the Prior Art
A quick mounting nut generally has radial inner engagement means which engages in a positive-locking manner in the outer thread of a bolt and which permits a screwing movement along the thread as the sole degree of freedom of movement of the nut which is positioned on the bolt. The nut is secured by the static friction of the thread with the engagement means of the axially clamped nut.
According to DE19737262A1, a facade fastening arrangement for mounting C-shaped sections has a wire clip with two springing legs which snap into elongated undercut openings of an axial supporting element in a friction-locking manner and positively engages therein. Such a force locking, snap-in fastening is unsuitable for threads with sloping flanks.
According to DE347859, a wire clip which is constructed as a wing nut for manual assembly engages in the threads of a bolt on both sides.
According to EP0084280, a springing wire clip, which has two legs and is constructed as a wire nut, engages in the threads of a bolt with both radial legs in the manner of a coil.
According to U.S. Pat. No. 3,880,041, a springing fastening element, which is constructed as a nut, contains in its hollow interior a wire clip which is wound coaxially in the shape of a coil and which engages in the threads. Axial positioning without screwing movement is not possible with these nuts.
According to DE-43-07-645, the wire clip of a quick mounting nut engages only partially in the threads, so that the quick mounting nut can be positioned axially by axial pressure.
According to DE19831001, a quick mounting nut with a wire clip, which is wound coaxially in the shape of a coil, is constructed as a self-locking wing nut in the interior of a nut housing and enables axial positioning without screwing movement, is secured by a screwing movement, and can be unlocked by a loosening torque acting along the wire clip. The engagement in the threads, which takes place only in a frictionally locking manner, does not permits to secure the quick mounting nut so that it would be able to withstand a load.
In order to fasten pipelines in installation rails, special rail nuts associated with the installation rails are used as part of a fastening system and are provided with a metric thread. A threaded rod or bolt serves as a connection element between the pipe clamp and the rail nut as well as for height adjustment. The threaded rods, which are supplied by the meter, are cut to the required length for mounting. As a result of cutting burs are formed and must be removed by cutting before screwing the rod into the rail nut. The cutting and height adjustment are very time-consuming.
DE4403974 discloses quick mounting nuts, which can be positioned axially to the threaded rod without being subjected to screwing movement. For this purpose, the engagement means of the quick mounting nut, which are constructed as threaded sectors and engage in the thread of the threaded rod in a positive-locking manner, can swivel out axially in a springing manner. After a screwing movement effected for securing the quick mounting nut, the swiveled-in engagement means, which are fixed at a stop, engage in a positive-locking manner in the thread of the threaded rod.
Further, DE4243185 discloses special rail nuts which are arranged inside the installation rails and comprise a pressure plate which is pre-mounted by snapping in for mounting on installation rails that are fixed on the outside of installation rails by another nut.
It is the object of the invention to further develop a quick mounting nut which fastens in a positive-locking manner.
Another object of the present invention is a quickly mounted fastening system for mounting at installation rails.
These and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a detachable quick mounting nut, which is movable axially relative to a threaded bolt and which comprises a springing wire clip within a nut housing with a coaxial through-opening, which wire clip partially engages in at least one thread, essentially has an inner cone which narrows radially within this continuous coaxial opening from the axial neutral position of the wire clip. The wire clip, which is movable axially to a limited extent, can contact at least partially the inner cone. The wire clip has two legs which spring relative to one another. Each of the legs, which extend almost parallel to each other, partially engages in the thread of the threaded bolt in a slightly radially friction-locking manner within the radial plane, so that the wire clip is displaceable partially axially in the inner cone by screwing movements.
As a result of this external positive movement conveyed through the inner cone, a screw-like, positive-locking fastening of the quick mounting nut takes place, with the wire clip engaging in the thread of the threaded bolt.
It is further advantageous that the wire clip is supported so as to be movable axially in a limited manner within a nut housing forming a manual nut.
A further advantage consists in that the nut housing comprises two shells which are guided so as to be movable relative to one another along the wire clip. One of these shells, serving as unlocking means, is a cover shell forming a wedge which is directed radially inward and which, in a first position, can be guided between the free ends of the legs of the wire clip so as to spread the latter against their pretensioning, so that the quick mounting nut can be positioned axially without a screwing movement. In the second position, the wire clip which is axially offset due to the directed rotation of the quick mounting nut and makes contact within the coaxial inner cone causes a positive engagement with the thread, so that the quick mounting nut can be secured and also loosened by screwing movements. The quick mounting nut is constructed so as to be switchable between the first position and second position, so that the connection can be canceled again.
The shells which are movable relative to one another are advantageously connected with one another via snap-in means which, in a further advantageous manner, form a guide along the wire clip embedded on the inside.
A fastening sleeve is advantageously formed integral coaxially on the side of the nut housing forming the inner cone. By means of this fastening sleeve, the quick mounting nut can be connected in a coaxially rotatable manner with a pressure plate or a rail nut constructed for mounting at installation rails.
In another embodiment, a cover shell advantageously has a radially expandable, coaxial outer cone sleeve with a radial outer circumferentially extending annular groove for the middle part of the wire clip in which the latter can be secured axially without tension. The outer cone sleeve is slit axially and can accordingly expand radially in a springing manner when the threaded bolt is inserted through it. In addition, the cover shell has a switching element in the radial outer area as fastening means for locking. When the switching element makes axial contact when actuated, the wire clip, which is supported on one side in an axially offset manner within the nut housing and which is secured axially in the annular groove is displaceable axially out of the annular groove to a limited degree and, through its own radial tension, automatically slides axially along the outer cone sleeve and engages in the threads.
The cover shell, with the radially expandable coaxial outer cone sleeve as actuating means for locking, advantageously has at least one, advantageously two, oppositely arranged, radially projecting, axially springing projecting arms which have, in the radial outer area, an axial bearing pin for the wire clip which is oriented toward the wire clip. These projecting arms in turn advantageously form expanding springing locking protuberances with which the radial outer areas of the wire clip can be snapped in in an axially fastening manner inside the legs, so that by actuating one of the projecting arms, or advantageously both of them simultaneously, the wire clip which is accordingly tensioned axially can be displaced axially out of the annular groove to a limited extent and slides over the outer cone into the thread.
The cover shell advantageously forms the gripping surfaces of the wing nut vertical to the projecting arms which are oriented along the wire clip.
In an advantageous alternative embodiment, a quick mounting nut is constructed as a plug-in rail nut with a cover shell securely connectable with the pressure plate via two webs of the quick mounting nut.
The webs are advantageously secured to the cover shell via respective film hinges. The webs hold the quick mounting nut at a predetermined distance from the pressure plate and are originally folded up during production and for easier preassembly.
The webs advantageously swivel a hold-down device, which is formed integral therewith, axially over the base shell of the quick mounting nut and press it against the wire clip, which is integrated therebetween inside the quick mounting nut and which is flexible axially to a limited extent accompanied by a slight axial pretensioning. The axially pretensioned gap which occurs between the two shells makes it possible to compensate the mounting thickness of the installation rails with a usual tolerance of about 0.4 mm when the plug-in rail nuts are mounted.
The quick mounting nut advantageously has teeth on the surface oriented in the direction of the base plate. Therefore, the wire clip makes possible, in addition, a pretensioned engagement of the teeth of the quick mounting nut in the counter-toothing of the installation rails. The wire clip accordingly combines the above-mentioned fastening function at the threaded rod with the mounting function at the installation rails by applying an axial pretensioning.
With respect to its basic shape, the quick mounting nut advantageously has a width which is slightly smaller than the opening of the C-shaped installation rails, so that the quick mounting nut can be inserted through the opening in the installation rail, and a length which is somewhat smaller than the inner dimension of the installation rail, so that the quick mounting nut which is oriented transverse to the rail axis can be supported in an axial positive engagement and is freely movable along the installation rail, and two diagonally opposed axial edges which are rounded corresponding to the circle of diameter Yxe2x80x2 which can be inscribed in the installation rail. As a result, the quick mounting nut which is introduced along the rail axis can be rotated into the installation rail only by turning clockwise. The nut is essentially prism-shaped.
An alternative fastening system for mounting at installation rails is advantageously constructed with two quick mounting nuts, wherein a first quick mounting nut which is constructed as a rail nut can be inserted into a C-shaped installation rail so as to be fixedly connected with the base plate. A second quick mounting nut, which is connected via the threaded rod inserted coaxially into both quick mounting nuts and which is constructed as a locking nut and can be screwed in by rotation, can be secured by static friction to the facing plane partial surfaces of the base plate and can be loosened again via unlocking means.
The two legs of the wire clip advantageously have an inclination which corresponds to that of the threaded bolt in order to ensure a positive-locking connection between the outer contour of the threaded bolt and the wire clip.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment, when read with reference to the accompanying drawings.